EP1194000A1 - Enceinte d'extremes-graves - Google Patents

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Publication number
EP1194000A1
EP1194000A1 EP01904535A EP01904535A EP1194000A1 EP 1194000 A1 EP1194000 A1 EP 1194000A1 EP 01904535 A EP01904535 A EP 01904535A EP 01904535 A EP01904535 A EP 01904535A EP 1194000 A1 EP1194000 A1 EP 1194000A1
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EP
European Patent Office
Prior art keywords
sub woofer
time length
block
signal processing
digital signal
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP01904535A
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German (de)
English (en)
Inventor
Kenji Murata
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Individual
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Individual
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Publication date
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Publication of EP1194000A1 publication Critical patent/EP1194000A1/fr
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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R1/00—Details of transducers, loudspeakers or microphones
    • H04R1/20—Arrangements for obtaining desired frequency or directional characteristics
    • H04R1/22—Arrangements for obtaining desired frequency or directional characteristics for obtaining desired frequency characteristic only 
    • H04R1/26—Spatial arrangements of separate transducers responsive to two or more frequency ranges
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R3/00—Circuits for transducers, loudspeakers or microphones
    • H04R3/04—Circuits for transducers, loudspeakers or microphones for correcting frequency response
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R3/00—Circuits for transducers, loudspeakers or microphones
    • H04R3/12—Circuits for transducers, loudspeakers or microphones for distributing signals to two or more loudspeakers
    • H04R3/14—Cross-over networks

Definitions

  • the present invention relates to a sub woofer system wherein a sub woofer, the output sound signal of that has been produced by digital signal processing involving therein a group delay, is connected to an analog audio reproduction system.
  • a speaker system of an audio reproduction system in order to obtain the range of plentiful low sounds, it has hitherto been carried out to construct the speaker system by adding a sub woofer to a main speaker unit.
  • the low pass filter used when adding the sub woofer there is used an analog passive filter comprised of a coil, a capacitor, and a speaker, or an analog active filter comprised of an amplifier, a resistor, and a capacitor.
  • a voice band passed through the added sub woofer is set so as to cover from 40 to 200 Hz inclusive. Therefore, the voice band that come above that frequency band are eliminated by the low pass filter.
  • the low pass filter there are two types, one of them is an analog type in which although no group delay occurs the phase varies with the filter gain, and the other is a digital type in which group delay occurs.
  • Many of the low pass filters that have been generally adopted. are the analog-type ones in which no group delay occurs.
  • the limitation upon the filter characteristic that can be practically used is to an extent of 24 db/oct.
  • the followings are known, too. Namely, because of the filter characteristic of the analog type filter, the sound at the crossover frequency and the sounds whose frequencies are in the vicinity thereof within the inhibition band of the sub woofer remain to exist while being subjected to rotation of the phase. These residual sounds make phase interference with the sounds within the pass band of the main speaker. Resultantly, adding the sub woofer causes degradation of the quality of the sound range undertaken by the main speaker.
  • a filter characteristic that is 10 times or more steeper than that of the analog type can be realized at a real time by the use of a DSP (Digital Signal Processor) or a CPU.
  • DSP Digital Signal Processor
  • FIR type or IIR type digital filter in which there is used the DSP or CPU it is possible to realize a steep filter without being accompanied by a degradation in the quality of sound that would occur in the analog type low pass filter.
  • the reason for this is as follows. Namely, because the sounds within the inhibition band of the sub woofer are rapidly attenuated, the interference between the sounds within the inhibition band of the sub woofer and the sounds within the pass band of the main speaker occurs only to a small degree. As a result of this, it is possible to prevent degradation in the quality of sound within the range of sound undertaken by the main speaker.
  • the present invention has been made in view of the above and has an object to provide a sub woofer system which has a construction that enables arbitrarily setting the group delay time length in the digital type real time digital signal processing part to thereby enable improving a phase interference between a main speaker and the sub woofer at a crossover point.
  • a sub woofer system which is mainly characterized in that the sub woofer system comprises a real time digital signal processing part that includes an A/D converter block, a low pass filter block, a delay block, and a D/A converter block, an analog power amplifier, and a speaker, whereby processing in the digital signal processing part is executed by setting the delay time length in the delay block so that the group delay time length in the digital signal processing part may be equal to an integral multiple of the time length corresponding to one wavelength of a crossover point frequency between the sub woofer system and a main speaker.
  • the present invention in the above-described construction, may be arranged to enable automatically setting the group delay time length and thereby enable manually minutely adjusting the set time length thereof. Also, in place of the above-described construction, the invention can be made up into the following construction, too.
  • a first example of the other constructions of the sub woofer system according to the invention is a sub woofer system (Fig. 2) having a construction comprising a real time digital signal processing part that includes an A/D converter block, a low pass filter block, a delay block, and a D/A Converter block, an analog power amplifier, and a speaker.
  • the delay time length in the delay block is automatically set so that the group delay time length in the digital signal processing system may be equal, among the time lengths represented by integral-multiple values of the time length (e.g. 1/100 sec.
  • a second example of the other constructions is a sub woofer system having a construction comprising a real time digital signal processing part that includes an A/D converter block, a low pass filter block, a delay block, and a D/A converter block, an analog power amplifier, and a speaker.
  • the delay time length in the delay block is automatically set so that the group delay time length in the digital signal processing system may be equal, among the time lengths represented by integral-multiple values of the time length (e.g. 1/100 sec.
  • the factor reflected by the group delay time length there is not only the difference in distance between the two speakers but also, in some cases, the difference between a phase angle of the main speaker itself and that of the sub woofer itself. Therefore, in the present invention, there is also a case where this difference in phase angle is calculated in terms of the time length and is reflected by the group delay time length.
  • the A/D converter block may be replaced with a digital audio interface block (DAI block), whereby it may be arranged that a digital signal transmitted from a reproduction medium such as a CD, a DVD, etc., a digital pre-amplifier, and a digital channel divider, etc. can be directly input to the sub woofer system.
  • DAI block digital audio interface block
  • an equalizer block for correcting to flatness the peaks and dips of the frequency response and/or phase response that is specific for a speaker unit used in the sub woofer or that is produced with a combination of the sub woofer and a speaker box, whereby, if necessary, the correction has its contents made manually minutely adjustable for producing a higher quality of sounds (Fig. 4).
  • the equalizer block to be added is in some cases used as means for correcting to flatness the descent in a low-sound range and making this correction manually minutely adjustable.
  • the power amplifier for use for the sub woofer can be replaced with an another arbitrary power amplifier.
  • the real time digital signal processing part is inserted to thereby construct the sub woofer system of the invention.
  • Fig. 1 is a block diagram showing an example wherein a sub woofer system according to the invention is applied to one example of an existing audio system.
  • Fig. 2 is a block diagram showing an example of the sub woofer system according to the invention that is employed in Fig. 1.
  • Fig. 3 is a block diagram illustrating another example of the sub woofer system according to the invention.
  • Fig. 4 is a block diagram showing still another example of the woofer system according to the invention.
  • Figs. 5 and 6 are block diagrams showing further examples of the woofer system according to the invention.
  • a reference numeral 1 denotes a playback detection part for an audio signal recorded in a recording medium such as a CD
  • a reference numeral 2 denotes a pre-amplifier connected to the detection part 1
  • a reference numeral 3 denotes a main amplifier connected to the pre-amplitier
  • a reference numeral 4 denotes a main speaker that is connected to the main amplifier 3 and that is of a multi-way type in the figure.
  • a system including every element from the playback detection part 1 to the main speaker 4 constitutes an example of a conventionally known audio system.
  • the sub woofer system of the invention is intended to obtain a reproduction low sound with an ample feeling of presence that cannot be obtained with the conventional analog type sub woofer system.
  • That sub woofer system has the following construction.
  • a reference numeral 5 denotes a real time digital signal processing part that handles a reproduction signal, which has been branched off from the pre-amplifier 2 in the above-described audio system, as an analog input signal to be processed thereby.
  • the real digital signal processing part includes the following elements.
  • a reference numeral 5a denotes an A/D converter that converts an analog audio signal, which is branched off and supplied from the pre-amplifier 2, to a digital signal
  • a reference numeral 5b denotes a digital low pass filter that, of the digital audio signals supplied from the converter 5a, permits the passage therethrough of only a digital audio signal having a frequency of, for example, 200 Hz or less and that inhibits the passage therethrough of a signal the frequency of that comes under the other frequency band
  • a reference numeral 5c denotes a delay block
  • a reference numeral 5d denotes a D/A converter that converts a digital audio signal, which has had its phase controlled by the delay block 5c, to an analog audio signal
  • a reference numeral 6 denotes a main amplifier of the sub woofer system of the invention
  • a reference numeral 7 denotes a speaker unit that serves as a sub woofer.
  • the low pass filter although either an FIR type or an IIR type is used
  • the digital low pass filter 5b because performing digital processing of a digital audio signal, a very steep filter characteristic is obtained.
  • the FIR type filter in the case of the FIR type filter, it can be made up into a construction of linear phase in which no phase rotation occurs as in the case of an analog type filter.
  • delay not only occurs when conversions by the both converters are made but, because a length of time is needed for performing digital processing of the signal, group delay also occurs. As a result of this, a time difference occurs between the resulting reproduction signal and the reproduction signal output from the main-speaker system.
  • variable type delay block 5c is inserted immediately after the low pass filter 5b.
  • the group delay in the filter 5b and the converters 5a and 5d is phase controlled there in terms of between the resulting reproduction signal and the reproduction signal from the main-speaker system.
  • the present invention thereby has enabled a reproduction sound in the range of low sound, which when listening they don't feel that it has a phase shift occurring due to the group delay, to be superimposed upon the reproduction sound of the main speaker 4.
  • the crossover point between the woofer of the main speaker 4 and the sub woofer 7 is, for example, 100 Hz.
  • a delay (with respect to the analog signal of the main speaker) is produced by the operation of the delay block 5c so that the total length of group delay time in the real time digital signal processing part may become a length of time of 1/100 sec. corresponding to one wavelength of the 100-Hz frequency, or an integral multiple thereof.
  • the delay block 5c thereby drives the sub woofer 7 by the main amplifier 6 thorough the D/A converter 5d.
  • Fig. 2 is a block diagram illustrating an arrangement in which only the sub woofer system of the invention of Fig. 1 is extracted.
  • the signal input to the A/D converter 5a may be taken in from other position than that of the pre-amplifier 2 of Fig. 1.
  • the A/D converter 5a cannot directly take in a digital signal such as that recorded in a CD or a DVD. Therefore, when directly taking in a digital signal, as illustrated in Fig. 3, a digital audio interface block (DAI block) 5a' is used in place of the A/D converter 5a.
  • DAI block digital audio interface block
  • the low pass filter block 5b, equalizer 5e, and delay block 5c are illustrated in their divided forms, the respective pieces of processing in the DSP 5 are ordinarily performed at the same time. Such pieces of processing may of course be performed at individually separate times.
  • the present invention is as has been described above. Namely, in the sub woofer system that performs real time digital signal processing, group delay occurs during a time period of digital signal processing, and phase interference occurs due to this group delay in the vicinity of a crossover point between the system and the main speaker.
  • a delay block is inserted into this real time digital signal processing system. Thereby, it is arranged to perform control of the length of a group delay time occurring in the digital signal processing system so that this length may equal an integral multiple of the length of time corresponding to one wavelength of the crossover point frequency signal between the system and the main speaker. By this control, the phase interference can be prevented from occurring.
  • the invention brings about the effect of widening the matched-phase range of sounds to a range from the pitch approximately 1 octave above the crossover point to the pitch approximately 1 octave below the same.
  • the frequencies of the sounds the pitches of that are below the pitch of the crossover frequency sound can be further sectioned into narrower bands, whereby the phases in the respective bands can be matched between such bands. It is thereby possible to further widen the range of sounds within which no phase interference occurs and they are heard as if having the same phase.

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  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Acoustics & Sound (AREA)
  • Signal Processing (AREA)
  • Health & Medical Sciences (AREA)
  • Otolaryngology (AREA)
  • General Health & Medical Sciences (AREA)
  • Circuit For Audible Band Transducer (AREA)
  • Obtaining Desirable Characteristics In Audible-Bandwidth Transducers (AREA)
  • Stereophonic System (AREA)
EP01904535A 2000-02-18 2001-02-19 Enceinte d'extremes-graves Withdrawn EP1194000A1 (fr)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
JP2000040494 2000-02-18
JP2000040494A JP2001231090A (ja) 2000-02-18 2000-02-18 サブ・ウーファ・システム
PCT/JP2001/001159 WO2001062041A1 (fr) 2000-02-18 2001-02-19 Enceinte d'extremes-graves

Publications (1)

Publication Number Publication Date
EP1194000A1 true EP1194000A1 (fr) 2002-04-03

Family

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Family Applications (1)

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EP01904535A Withdrawn EP1194000A1 (fr) 2000-02-18 2001-02-19 Enceinte d'extremes-graves

Country Status (4)

Country Link
US (1) US6771784B2 (fr)
EP (1) EP1194000A1 (fr)
JP (1) JP2001231090A (fr)
WO (1) WO2001062041A1 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1732354A1 (fr) * 2005-06-09 2006-12-13 TCL Thomson Electronics Europe SAS Appareil monolithique avec système acoustique

Families Citing this family (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR100945751B1 (ko) * 2002-12-24 2010-03-08 삼성전자주식회사 컴퓨터장치
US20040175152A1 (en) * 2003-03-04 2004-09-09 Haw-Renn Chen Method and apparatus of versatile audio video system
US8170233B2 (en) * 2004-02-02 2012-05-01 Harman International Industries, Incorporated Loudspeaker array system
JP2006014367A (ja) * 2005-08-05 2006-01-12 Pioneer Electronic Corp 音声データ処理方法
KR100813272B1 (ko) * 2006-12-20 2008-03-13 삼성전자주식회사 스테레오 스피커를 이용한 저음 보강 장치 및 방법
US20100229008A1 (en) * 2009-03-06 2010-09-09 Tsuoe-Hsiang Liao Sound Effect Power Supply Configuration
US9337793B2 (en) * 2012-01-17 2016-05-10 Jack Nilsson Orthogonal ergonomic speaker
US9524098B2 (en) 2012-05-08 2016-12-20 Sonos, Inc. Methods and systems for subwoofer calibration
CN102724607A (zh) * 2012-06-12 2012-10-10 东莞市龙健电子有限公司 一种数字矩阵音箱管理器
TWI651970B (zh) * 2017-01-25 2019-02-21 佳世達科技股份有限公司 分音裝置

Family Cites Families (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1516935A (en) * 1976-03-24 1978-07-05 Decca Ltd Loudspeaker systems
JPS61244193A (ja) * 1985-04-22 1986-10-30 Matsushita Electric Ind Co Ltd 音質調整装置
JPH1011078A (ja) * 1996-06-20 1998-01-16 Sony Corp 音響装置用調整装置
US5910991A (en) * 1996-08-02 1999-06-08 Apple Computer, Inc. Method and apparatus for a speaker for a personal computer for selective use as a conventional speaker or as a sub-woofer
FI105522B (fi) * 1996-08-06 2000-08-31 Sample Rate Systems Oy Järjestely kotiteatteri- tai muussa äänentoistolaitteistossa
JP3556427B2 (ja) * 1997-04-08 2004-08-18 アルパイン株式会社 オーディオ装置の制御帯域決定方法
JP3513850B2 (ja) * 1997-11-18 2004-03-31 オンキヨー株式会社 音像定位処理装置および方法
US6546298B1 (en) * 1998-06-17 2003-04-08 Micron Technology, Inc. Speaker apparatus and a computer system incorporating same
US6687379B1 (en) * 2001-05-04 2004-02-03 Thiel Audio Products System and method for adjusting the low-frequency response of a crossover that supplies signal to subwoofers in response to main-speaker low-frequency characteristics

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO0162041A1 *

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1732354A1 (fr) * 2005-06-09 2006-12-13 TCL Thomson Electronics Europe SAS Appareil monolithique avec système acoustique

Also Published As

Publication number Publication date
US6771784B2 (en) 2004-08-03
JP2001231090A (ja) 2001-08-24
US20020141605A1 (en) 2002-10-03
WO2001062041A1 (fr) 2001-08-23

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